Electrochemical process fob separating- iron from aluminum



l etonteci Sept. 25, E 28.

eanne FRAAHTESCG GIDRDANI, O13 NAILES, ITALY ASSIGNGR TO POMILIG BROTHEBE PGRATION, OF NEW YORK, Y.,

A CORPORATION Ci? NEW YGEK.

EILEGTRQCEEMICAL PROCESS ER SEPARATIKG 1R0}? FRGM ALUMINUM.

5 g my from the solutions of their salts, opera g in such a way that no impurities may nto the precipitated mass. The advante a e of this proc s from an economic standpoint is tll'P'DfiSlbilltjV of using as a substi- 1G tote element which replaces in the solution the metal being precipitated, another metal less costly.

Such properties, according to the present invention. can in some cases find an uppliew tion which is precisely the inverse of that above descrihed: We can have for instance the ease in which, in View of the proposed further treatment of the salt of the principal metal. it may he necessary to eliminate the impurities which are contained in it, and. in order to eliminate these, we can conduct the operation 0 dissolve a further quantity of the one o greater value. a quantity that may A .{t to replace the metals constituting spur ies which are to be precipitated, obtaining a pure solution which can be dirertly suliieeted to the further proposed metallurgical operations. Only it musthe noted in such a csse in order to render more energetic the action which might take place very slowly' because of the small. coneentration of the ions and because of the phenomena of polarization, it is desirable to resort to a. reel voltuic couple short circuited.

In order to be precise, let us assume a solution comprising salts of the metallic elements A, B. C, and let us suppose that we wish to eliminate the element A which is present in small quantity, thus practically constituting an impurity. and such' as to have a solution tension inferior to that of the other elements l C,' To this end i 13 provide in the, liquor a volteic couple with two metallic plates, one made of the element A, which We wish to eliminate. and which functions as positive pole. the other mode of one of the elements l3 preferably of that element having? the highest tension of solution. Then this letter electrode being negative, will send into solution some ions displacing those of the element A which will pass to and are deposited on the positive electrode, which'may he constituted of carbon or of any metal harmg a solution tension lower than A.

Application filed August 25, 1922 Serial No) 554,382

A. practical case in which, as n examine the method of purification above descrih finds convenient application is that of elimination of the iron from the liquor o noted from the ncid attack of the leueites Mid of aluminum-potassium silicates in general, with the scope of obtaining from them the pure aluminum hydroxide up to of p itv such as it is required for the menu hie, of aluminum in the electric furnaces. for ti preparation of the salts used as nmrdu other similar uses, this process heir: 1 forth in any (o-pending applicehon 58 -386 of even date herewith and in Putz 1.556.543 and 1,559,??? to Umberto l-"orrm and myself,

The liouors obtained from the acid trout ment of the rocks are convenientlv neutml ized so as not to contain any free acid. and a e passed into appropriate tanks in which are plunged electrodes of aluminum and; carbon (graphitel connected to form a circuit.

A voltaic couple is then formed:

Aluminum liquor/graphite The aluminum passes into solution in the state of ions AP in a first stage at the expense of the reduction of the ferric shit to ferronn salt and successively displaeingr the iron {ions Fe from the solution. while 6' these latter ions go to deposit themselves on the carbon. M

Through this process is possible to recover a liquor containing 0111 the salts of aluminum and potassium.

The electrirritv generated hv the volteie couples above described max also he recow ered by connecting them appropriateiv to storage batteries or other instrumentnlities appropriate for the storage or utilization of 95 electric energv.

What I elnim isz- In a process for purifying solutions connluminum salts. positioning sisting mainly of therein an electrode of aluminum and another 9 adapted to act as positive electrode for a metal to be eliminated and connecting them in circuit, substantially as set forth.

In witness whereof l have hereunto set my hand at Naples Italy, this 15th day of 185 October, A. D. nineteen hundred and twenty one.

FRANGESOO G-IORDANI. 

